CVE-2020-3120 : What You Need to Know
Learn about CVE-2020-3120, a high-severity vulnerability in Cisco IOS XR Software that allows adjacent attackers to cause a denial of service condition by reloading affected devices.
A vulnerability in the Cisco Discovery Protocol implementation for Cisco FXOS Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition by reloading an affected device.
Understanding CVE-2020-3120
This CVE involves a vulnerability in the Cisco Discovery Protocol implementation that could lead to a DoS attack on affected devices.
What is CVE-2020-3120?
The vulnerability allows an unauthenticated attacker in the same broadcast domain as the affected device to send a malicious Cisco Discovery Protocol packet, causing the device to reload due to memory exhaustion.
The Impact of CVE-2020-3120
- Severity: High (CVSS Base Score: 7.4)
- Attack Vector: Adjacent Network
- Availability Impact: High
- The vulnerability could result in a denial of service condition by reloading the affected device.
Technical Details of CVE-2020-3120
This section provides technical details of the vulnerability.
Vulnerability Description
The vulnerability is caused by a missing check in the affected software when processing Cisco Discovery Protocol messages, allowing an attacker to exploit it through a malicious packet.
Affected Systems and Versions
- Affected Products: Cisco IOS XR Software
- Vendor: Cisco
- Versions Affected: Less than 2.3.1.173
Exploitation Mechanism
- The attacker needs to be in the same broadcast domain as the affected device (Layer 2 adjacent).
- By sending a malicious Cisco Discovery Protocol packet, the attacker can exhaust system memory, leading to a device reload.
Mitigation and Prevention
Protecting systems from this vulnerability requires immediate steps and long-term security practices.
Immediate Steps to Take
- Apply vendor patches and updates promptly.
- Implement network segmentation to limit broadcast domain exposure.
- Monitor network traffic for any suspicious activity related to the Cisco Discovery Protocol.
Long-Term Security Practices
- Regularly update and patch all software and firmware.
- Conduct security awareness training to educate users on potential threats.
- Implement access controls and authentication mechanisms to restrict unauthorized access.
Patching and Updates
- Cisco has released patches to address this vulnerability. Ensure all affected systems are updated with the latest security fixes.